A quick search on Google will bring up countless ways to make DIY speakers (or volume boosting amps) for a smartphone. From a paper cup to a glass jar, nearly all of these will give you some extra volume, but which ones work best? We decided to test out a few of the most popular tricks.

To test the volume, we're using the not-entirely-scientific iPad app Decibel Meter Pro to check sound levels from an iPhone 4S's speaker. We'll also use the same song for each method, The Beatles "Helter Skelter" since it starts out nice and loud with the peak around the 12 second mark. Each different amp had its sound directed at the iPad as best as possible.

The average decibel level in the room prior to playing music was 51. With that, let's take a look at the results.

No Amp

Our first test was just the iPhone sitting with no amp on a tabletop. This result of a decibel level of 59 will be our baseline for the amps from here on out.

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Decibel Level: 67Decibel Change: +8Sound Quality: Poor. It was louder, but the two different glasses we tested it with created an echo effect that was hard to ignore.

Make-Shift Cardboard Amp

When I last worked in an office I only had an ancient PC with a barely functional copy of Windows XP installed on it and no music player. This cardboard construction was my solution. I figured I'd introduce it into the test to see how it faired. It's an oatmeal box cut to fit around the iPhone and project the sound.

Decibel Level: 67Decibel Change: +8Sound Quality: Good. The sound quality doesn't change much but it carries well across the room and kept a good mix of the highs and lows.

Paper Cup

37 Signals programmer Sam Stephenson posted the coffee cup as iPhone amp a while back. It might not seem like paper would boost volume better than the other methods, but it ended up being the loudest in our tests and sounds good.

Decibel Level: 72Decibel Change: +13Sound Quality: Good. The paper cup was not only the loudest it also sounded the best regardless of where we were in the room. Quality was on par with non-powered speakers I've heard.

As we noted at the beginning, this isn't exactly the most scientific test in the world and your mileage may vary. For our conditions the paper cup was not just the loudest, but also the best sounding. None of these methods make listening to music great but they do offer a boost so you can hear better.

We've seen quite a few of these tricks over the years so if we missed your favorite method sound off in the comments. If you want to test and post your own results, please do.